MessageDialog doesnt handle onAccepted and onRejected

I created the attached example:

current behaviour:

a MessageDialog is called on a clicked inside a Mouse Area. The MessageDialog is opened ok, but clicking any defined button (Ok or Cancel) is not calling any of   handles onAccepted: console.log("Accepted")
onRejected: console.log("Rejected")

One must define onButtonClicked: function(button, role).. in order to be able to handle the onAccepted or onRejected (see the attached example).

Expected behaviour:

One can write onAccepted or onRejected handles in MessageDialog without the use of onButtonClicked.